[stable-only] Revert "spi: rockchip: modify DMA max burst to 1"

This reverts commit 86766cbb.

Not suitable for 4.2: no max_burst.
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/spi/spi-rockchip.c

@@ -199,7 +199,6 @@ struct rockchip_spi {
 	struct sg_table rx_sg;
 	struct rockchip_spi_dma_data dma_rx;
 	struct rockchip_spi_dma_data dma_tx;
-	struct dma_slave_caps dma_caps;
 };
 
 static inline void spi_enable_chip(struct rockchip_spi *rs, int enable)
@@ -455,10 +454,7 @@ static void rockchip_spi_prepare_dma(struct rockchip_spi *rs)
 		rxconf.direction = rs->dma_rx.direction;
 		rxconf.src_addr = rs->dma_rx.addr;
 		rxconf.src_addr_width = rs->n_bytes;
-		if (rs->dma_caps.max_burst > 4)
-			rxconf.src_maxburst = 4;
-		else
-			rxconf.src_maxburst = 1;
+		rxconf.src_maxburst = rs->n_bytes;
 		dmaengine_slave_config(rs->dma_rx.ch, &rxconf);
 
 		rxdesc = dmaengine_prep_slave_sg(
@@ -475,10 +471,7 @@ static void rockchip_spi_prepare_dma(struct rockchip_spi *rs)
 		txconf.direction = rs->dma_tx.direction;
 		txconf.dst_addr = rs->dma_tx.addr;
 		txconf.dst_addr_width = rs->n_bytes;
-		if (rs->dma_caps.max_burst > 4)
-			txconf.dst_maxburst = 4;
-		else
-			txconf.dst_maxburst = 1;
+		txconf.dst_maxburst = rs->n_bytes;
 		dmaengine_slave_config(rs->dma_tx.ch, &txconf);
 
 		txdesc = dmaengine_prep_slave_sg(
@@ -743,7 +736,6 @@ static int rockchip_spi_probe(struct platform_device *pdev)
 	}
 
 	if (rs->dma_tx.ch && rs->dma_rx.ch) {
-		dma_get_slave_caps(rs->dma_rx.ch, &(rs->dma_caps));
 		rs->dma_tx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_TXDR);
 		rs->dma_rx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_RXDR);
 		rs->dma_tx.direction = DMA_MEM_TO_DEV;